The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
In some mobile devices, e.g., mobile phones, a user interface may be adapted for detecting headset or headphone plug into the device. Headsets may thus embed push buttons (called hookswitch), which may be used not only to initiate or terminate calls, but also to control the music player (and operate functions such as “play”, “pause”, “mute”, etc.). A process of detecting the headset/headphone presence and any button press may run permanently, with the constraint of thus being a low power process. In addition, the headset/headphones are nowadays available mainly with male jack connectors, for instance with 2.5 mm or 3.5 mm diameter plug.
A solution which may be employed for detecting headset/headphone presence may use a specific female jack connector integrated in the phone. Such a female jack connector may be specific in that a contact is added in the connector which comes open or closed depending on whether a male jack plug is inserted or not. This contact allows detecting headset/headphone presence.
An alternative solution may consist in detecting the headset by analyzing the microphone presence. In fact the microphone line could be open when nothing is plugged, resistively loaded to a few kilo-ohms when the headset microphone (or mike) is connected, resistively loaded to a few hundreds ohms when the headset buttons are pressed, and nearly shorted to ground when headphone is plugged.
The use of specific female jack connector only teaches about jack male presence or insertion. Hence, it is not useful to distinguish between headset, headphone and button press. Even if it allows a low power detection of jack male presence, concluding about the effective accessory being connected or about the state of buttons would require use of analog to digital conversion which is current consuming. This current consumption could be problematic because of permanent detection requirement. In addition, the presence of the specific presence contact on this female jack connector raises the cost of said jack connector.
The above alternative solution consisting in detecting the microphone presence allows the use of the most basic and lowest cost female jack connector, because no specific contact is required. It allows a full detection of the accessory plugged-in as well as the acquisition of button press state. Finally, it exhibits low current consumption, particularly when the detection is pulsed.
However, this solution shows a particular drawback depending on how the jack male connector is inserted in the phone. This phenomenon is known as “sliding effect”. During insertion, the male jack is in fact sliding inside the female plug. As the jack contacts are populated across the length of connector, the electrical connection of all contacts is sequential. In addition, the sequence of contact connection is false while jack male is not fully inserted in the female connector. For example, the tip contact of male jack (top contact) slides on all ring contacts of the female connector before being effectively linked to the tip contact of the female plug.
Effective issues of sliding effect comprise wrong detection of the headset and hook switch when the headset is plugged. It is observed, indeed, that the male connector rings cross different contacts and makes short cut which may result in connection between the headset left channel and the microphone for example.
There is a need in the art to address at least some of the above problems. In particular, embodiments allow avoiding the above described sliding wrong detection phenomenon.